Manufacture of electric cables



Am! 14, 1931. I FHANFF r 1,800,347

MANUFACTURE OF ELECTRIC CABLES Filed Sept. 28, 192 2 Sheets-Sheet l April 141931; F. ANFF 1,800,341

MANUFACTURE OF ELECTRIC CABLES Filed Sept. 28, 1926 2 Sheets-Sheet 2 Patented Apr. 14, 193 1 UNITED sT rss PATENT OFFICE FERDINAND HANFF,OFBERLIN-CHARLOTTENIBUBG, GERMANY, ASSIGNOR '10 BIEMENS- I BOEUCKERTWEBKE GESELLSCHAFT HIT BESCHRKNKTER HAFTUNG, OF SIEMENS- STADT, NEAR BERLIN, GERMANY, A CORPORATION. or

MANUFLCTUBE DIELECTRIC CABLES Application filed September, 1926 Serial No. 188,194, and in Germany October 5, 1925.

Mly invention relates to the manufacture of e ectric cables.

In the hitherto employed methods of man- Y ufacturin electric cables, particularly such [to which t e insulation is applied in several layers, it is impossible to keep the insulation covering free from wrinkles or crimps. It is well known that when apflying the insulating covering the core is rawn through the 10.ca le machine by means of apull-ofi wheel I positively coupled with the machine and is then wound upon a drum or reel. In these processes the conductorof the cable is considerably bent which causes more'or less deep wrinkles or cracks in the insulatmg covering. This distrubs the homogeneity of the insulation and the dielectric strength and thus. reduces the working reliability of the cable. y

I The same drawback when the cable conductor is coiled into charging baskets if their diameter is not made excessively lar e. a Theenlargement of the. diameter ca s, however, for extraordinarily large and. 15 expensive dry and saturating or impregnating vessels w 'ch in the present day cab e construction have already assumed unwieldy. dimensions.

a It has already been attempted to avoid or so at least reduce to a minimum the wrinkling or crackingl of the insul' ation by a 'udicious choice of t e quality of the paper, .t e width and the manner of wrapping it around (tight or loose with 0 en or over appin tape helices). It'has so been propose ,to reduce the curvature of the parts over which the cable must be bent viz. the pulling-ofi wheel and the" drum. 'All these expedients have,

however, not produced an entirely'satisfacto result.

in view is attained drawbacks. This end by avoiding the bending of the cable in the process of manufacture as long as the insulation upon it has 'not yet been saturated or impregnated. The cable conductors are thus passed neither over the customary pull-ofi wheel nor are they wound upon a cable drum. After leaving the stranding machine and subsequently the insulating machine (paper y improved method eliminates all these.

tape wra ping machine), the cable core is drawn 0 in the same direction and in as straight a line as possible and conducted into a vessel or chamber for dryin and impregnating the insulation, preferabl in one operation. This vessel has a lengt which corresponds with the manufacturing length of the cable.

In the drawings afiixed hereto apparatus suitable for carrying out my improved method is diagrammatically shown by way of example; These drawings illustrate in:

Fig. 1, a complete plant for manufacturing cables,

Fig. 2, a cross-section through a drying and impregnating vessel, ig. 3, a cross-section through a modification of such a vessel, v

Fig. 4, a. cross-section through a'further modification of-such a vessel,

Fig. 5, a longitudinal section corresponding with Fig. 4, and in ig. 6, a sectional side-elevation of a dryinichamber. a

' ike parts are indicated by like letters of reference in all the figures of the drawsigned as a continuous tube, which after-the insertion of the cable core e is .closed at both ends by caps f indicated in broken lines.

Tofacilitatetheintroductionofthewrapped cable a into the tubular chamber d, a rope winch h is provided at the far end of the chamber which serves as a relay and drags the cable through-the chamber (1 by the aid of a wire cable 9. It is, however, equally well possible to emplo an. endless chain driven by a motor g for ceding the cable into 100 the chamber upon which chain the cable rests and which is driven by suitable gearing. One length of this chain may run for instance upon rollers disposed in the chamber d. Durmg the drying and impregnating process which Occurs in chamber d the links of the chain at the ends of the tube are disconnected to permit the closing of the tube bythe caps f. The links may be disconnected. 1n the same simple manner in which the conventional hinge link typeof chain is opened, namely by pulling the cotter pin usually provided at the ends of the hinge pins, and by then pulling out the hinge or coupling pin.

An extensive tube as drying and impreg nating vessel has the advantage that it is able to withstand the pressure and partial boiler-shaped drying vacuum necessary for drying and impregnating the cable without excessive wall thickness. This is an important advantage in comparison with the hitherto employed and im regnatin vessels the wallsof which must made 0% considerable thickness. As tubes, may be emcommercial wrought- 1ron tubes procurable at a comparatively very low price.

In such a tube in which a single cable or a plurality taneously, the drying and impregnating process with application of pressure or vacmg may be considerab y reduced as com--' ing uum ma be carried out 1n considerably shorter time than in the hitherto customary apparatus. By employing heating and coolmg pipes within the drying tube or a heating or cooling jacket around the tube the time. necessary for drying, im regnating and coatpared with the time necessary for boilershaped drying and impregnating vessels.

Referring to Fig. 2 of the drawing the tube d is shown in cross-section with the cable e and pipes k whi'chcan be used for conduct- 1 gas, heating or cooling medium.

' eferring to Fig. 3 of the drawing, the tube 01 containing the cable e is surrounded I by a heating or cooling jacket 4'. This con-' particularly suitable,

struction of the tube for electric heating by distributing various heating elements over the tube. In this way a great uniformity, steadiness and regulating capacity of the heating along the entire len h of the tube is ensured.-

eferring to the Figures 4 and 5 thecable 1s shown resting upon the endless 0 sin servfor introducingthe cable intothe tube. The cable a rests upon bolsters carrying the. axles m of the wheels n which serve at the same time as cou ling plus for the links of the chain.

Fig. 6 of the drawin shows the tube'd and thelinkchain trave 'n through it and supporting the cable e.' I e chain is provi ed with two removable coupling pins as the of which is equal to the ength oi of cables may be located simultube of a length i lengthofthe manufactured cable and being tated by disposing the tube at a slight angle to the horizontal. This is not especially shown in the drawings, one skilled in the art. This arrangement has the further advantage that air contained in the tube whichmight have a detrimental efl'ect upon the cable is able to escape during the impregnating process. In order to avoid a deviation from the straight line the entire cable machine may be disposed at the same angle of inclination to the'horizontal. Since, however, even with a horizontal arrangement of the cable machine and an in-- clined arrangement of the tube d the change of direction of the cable from a straight line takes place at an infinitely lar e radius, no detrimental crimping or wrinkling of the cable insulation need be feared.

The fully impregnated or saturated, flexible cable can now be withdrawn from the ing the cable away from the cable machine 1n a strai ht line, a d g and impregnating tube of a length corr e s p onding at least to the length of the manufactured cable-and being di osed in straight alinement with the cable an d an endless chain for guiding the cable through said tube.

2. In an impregnating device for finished cables, a plurality of feed rollers for convey;

ing the cable away froin the cable machine m a straight line,

corresponding at least to the sed in straight alinement with the cable an endless chain forguiding the cable through said tube, the chain portion supportin the cablewhen in the tube being dedis a drying and impregnating being obvious to anytachab e from its remainder and means for closing the tube at both ends.

, 3. In an impregnating devicefor finished cables,'a plurality of feed rollers f or conve ing the cable away from thecable machine in a straight line a ym ani m 're n tube of a length correspondingat li H ,7 length of the cable and being ing the cable when in the tube being detachable from its remainder and means vfor closing the tube at both ends, and means for pulling the chain and cable in a straight line into and out of said tube.

4. In an impregnating device for finished cables means for conveying the cable away from the cable machine in a straight line, a drying and, impregnating tube of a length corresponding at least to the length of the manufactured cable and bein disposed in straight alinement with the ca 1e and means for conveying the cable in a straight line through said tube, and pi es running in parallel through said tube or maintaining the desired temperature in the tube during the impregnating process.

In testimony whereof I aflix m si%ature. FERDINAND h FF. 

